#include <stdio.h>

void RealSwap(double *x, double *y);

int main()
{
    double a, b;
    scanf("%lg%lg", &a, &b);
    RealSwap(&a, &b);
    printf("%g %g\n", a, b);
    return 0;
}

/* 你提交的代码将被嵌在这里 */
void RealSwap(double *x, double *y)
{
    double t = 0;
    t = *x;
    *x = *y;
    *y = t;
};
